The Trunk: Kernel-nice.424.mcz

Nicolas Cellier uploaded a new version of Kernel to project The Trunk:
http://source.squeak.org/trunk/Kernel-nice.424.mcz

==================== Summary ====================

Name: Kernel-nice.424
Author: nice
Time: 14 March 2010, 11:19:27.192 pm
UUID: 0ed744aa-5d6e-470a-9adc-a064c3d874df
Ancestors: Kernel-laza.423

Cache well known digit values in NumberParser for speed.
Testing the base as of previous implementation was not a good idea, because some Unicode characters could have a digitValue < 10.

=============== Diff against Kernel-laza.423 ===============

Item was added:
+ ----- Method: NumberParser classSide>>initializeDigitValues (in category 'class initialization') -----
+ initializeDigitValues
+ "Initialize the well known digit value of ascii characters."
+
+ DigitValues := Array new: 256 withAll: -1.
+ 0 to: 255 do: [:i | DigitValues at: i + 1 put: (Character value: i) digitValue]!

Item was added:
+ ----- Method: NumberParser classSide>>initialize (in category 'class initialization') -----
+ initialize
+ self initializeDigitValues.!

Item was changed:
  ----- Method: NumberParser>>nextElementaryLargeIntegerBase: (in category 'parsing-large int') -----
  nextElementaryLargeIntegerBase: aRadix
  "Form an unsigned integer with incoming digits from sourceStream.
  Return this integer, or zero if no digits found.
  Stop reading if end of digits or if a LargeInteger is formed.
  Count the number of digits and the position of lastNonZero digit and store them in instVar"
 
+ | value digit code char |
- | value digit |
  value := 0.
  nDigits := 0.
  lastNonZero := 0.
+ DigitValues ifNil: [self class initializeDigitValues].
+ "Avoid using digitValue which is awfully slow"
+ [value isLarge or: [(char := sourceStream next) == nil
+ or: [code := char charCode.
+ digit := code < 256
+ ifTrue: [DigitValues at: 1 + code]
+ ifFalse: [char digitValue].
+ (0 > digit or: [digit >= aRadix])
+ and: [sourceStream skip: -1.
+ true]]]]
+ whileFalse: [
+ nDigits := nDigits + 1.
+ 0 = digit
+ ifFalse: [lastNonZero := nDigits].
+ value := value * aRadix + digit].
- aRadix <= 10
- ifTrue: ["Avoid using digitValue which is awfully slow"
- [value isLarge or: [sourceStream atEnd
- or: [digit := sourceStream next charCode - 48.
- (0 > digit
- or: [digit >= aRadix])
- and: [sourceStream skip: -1.
- true]]]]
- whileFalse: [nDigits := nDigits + 1.
- 0 = digit
- ifFalse: [lastNonZero := nDigits].
- value := value * aRadix + digit]]
- ifFalse: [
- [value isLarge or: [sourceStream atEnd
- or: [digit := sourceStream next digitValue.
- (0 > digit
- or: [digit >= aRadix])
- and: [sourceStream skip: -1.
- true]]]]
- whileFalse: [nDigits := nDigits + 1.
- 0 = digit
- ifFalse: [lastNonZero := nDigits].
- value := value * aRadix + digit]].
  ^value!

Item was changed:
  Object subclass: #NumberParser
  instanceVariableNames: 'sourceStream base neg integerPart fractionPart exponent scale nDigits lastNonZero requestor failBlock'
+ classVariableNames: 'DigitValues'
- classVariableNames: ''
  poolDictionaries: ''
  category: 'Kernel-Numbers'!
 
+ !NumberParser commentStamp: 'nice 3/14/2010 22:42' prior: 0!
- !NumberParser commentStamp: 'nice 2/25/2010 02:34' prior: 0!
  NumberParser is an abstract class for parsing and building numbers from string/stream.
  It offers a framework with utility methods and exception handling.
 
  Number syntax is not defined and should be subclassResponsibility.
 
+ Note that class variable DigitValues is a duplication of Character class variable. This is only an optimization, decoding digitValues being a major contributor of algorithm cost.
+
  Instance variables:
  sourceStream <Stream> the stream of characters from which the number is read
  base <Integer> the radix in which to interpret digits
  neg <Boolean> true in case of minus sign
  integerPart <Integer> the integer part of the number
  fractionPart <Integer> the fraction part of the number if any
  exponent <Integer> the exponent used in scientific notation if any
  scale <Integer> the scale used in case of ScaledDecimal number if any
  nDigits <Integer> number of digits read to form an Integer
  lasNonZero <Integer> position of last non zero digit, starting at 1 from left, 0 if all digits are zero
  requestor <TextEditor | nil> can be used to insert an error message in the requestor
  failBlock <BlockClosure> Block to execute whenever an error occurs.
+ The fail block can have 0, 1 or 2 arguments (errorString and source position)
+
+ Class variables:
+ DigitValues <Array of: Integer> this is a mapping character asciiCode + 1 -> digit value (or -1 if character is not a digit)!
- The fail block can have 0, 1 or 2 arguments (errorString and source position)!